It is conventional, as disclosed in JP-A-2009-46050, for example, to arrange closely an electric motor and an electronic control unit, which are mounted in a vehicle, so that a loss of power caused by a wiring resistance, an increase of noise or an increase in the number of component parts may be reduced.
In a case that the electric motor and the control unit are arranged closely as in the above-referred patent document, the control unit occasionally need be placed at a position where water droplets fall depending on the position where the electric motor is mounted.
According to the patent document, therefore, a waterproof cover is provided to prevent water droplets from entering into the control unit. This waterproof cover necessarily increases the number of component parts.